The present disclosure relates to an image pickup element, an imaging apparatus, a manufacturing apparatus for the image pickup element, and a manufacturing method for the image pickup element. More specifically, the present disclosure relates to an image pickup element, an imaging apparatus, a manufacturing apparatus for the image pickup element, and a manufacturing method for the image pickup element that enable suppression of deterioration in quality of captured images.
In relate art, in order to enhance sensitivity and shading characteristics of a solid-state image pickup element, there have been developed a method of reducing a distance between a condenser lens (microlens) and a photodiode (PD) that are provided in each pixel (i.e., a method of reducing height of solid-state image pickup element). In order to suppress deterioration in light collection efficiency, which may be caused by such height reduction, the possibility of increasing a refractive index of the microlens has been investigated.
Specifically, the possibility of forming the microlens with use of a silicon nitride (SiN) inorganic film having a high refractive index has been investigated. However, in that case, the microlens is difficult to form with high accuracy without a planarizing film configured to planarize surfaces of color filters (refer to, for example, Japanese Patent Application Laid-open No. 2008-277800). In addition, this planarizing film needs to have a film thickness of from approximately 200 nm to 300 nm so as to planarize the surfaces of the color filters. Therefore, height reduction of the solid-state image pickup element has been difficult to achieve.
In view of the circumstance, the possibility of forming the microlens with use of a resin system containing fine metal particles (refer to, for example, Japanese Patent Application Laid-open No. 2008-060464). In the case of using the resin system containing fine metal particles, the microlenses can be formed by spin coating, and hence is not liable to be influenced by steps on the surfaces of the color filters. Thus, the microlens can be formed with high accuracy without the planarizing film. As a result, height reduction of the solid-state image pickup element can be achieved.